1. Field of the Invention
The present invention relates to a cassette, particularly for a printing mechanism provided with a thermal printing head, with a ribbon reel and a ribbon take-up reel.
The present invention also relates to a postage meter machine which includes the cassette.
2. Description of the Related Art
Ink ribbons and similar comparatively thin ribbons or tapes are used in a variety of devices, particularly also in postage meter machines. The ribbons usually constitute a material which is used up, i.e., they must be replaced or reloaded from time to time. In order to simplify these maintenance operations, reels onto which the ribbons (usually commercial products) are wound are mounted by the manufacturer in cassettes. The cassettes are then placed by the final user in the respective machine or device which receives the cassette and the cassette is connected to the drive of the device, and the reels are removed from the device after the ribbon material has been used up. When the cassettes and the station which receives the cassette are constructed appropriately, this exchange of cassettes is simple and can be carried out without special knowledge or capabilities.
However, a disadvantage is the fact that the conventional cassettes are usually designed as disposable elements. Since the costs of the cassettes are frequently not negligible in comparison to the ribbon material, and since the disposal of the ribbons may be a burden to the environment, this single use is not optimal. Unfortunately, particularly also those rechargeable cassettes of various types which have already been proposed some time ago do not constitute a suitable replacement for disposable cassettes because they are either too complicated in their construction, unsafe to operate, too cumbersome to use, i.e., particularly during recharging, or they are expensive, particularly with respect to their manufacture.
PCT/CH98/00278 discloses a cassette with an insert device which has made it possible more recently to facilitate by means of an adjustable ribbon guide means the insertion of the thin ribbons used today when inserting them into the cassette in the position of operation without damaging the ribbons. However, this cassette is structurally complicated and expensive as a result.
Therefore, it is the primary object of the present invention to propose a cassette which does not have the disadvantages mentioned above. It is also an important object that the cassette has a robust and simple construction which facilitates without problems the insertion or removal of a new ribbon or a new ribbon reel. Moreover, a device, particularly a postage meter machine, is to be proposed which because of the exchangeable and rechargeable cassette can be operated easily by the user, does not harm the environment and can be operated economically.
In accordance with the present invention, the cassette includes a housing composed of two wall portions which are spaced apart from each other, wherein the wall portions have grooves, integrally formed indentations or slots, wherein outer portions of the ribbon reel or take-up reel are supported in the grooves or indentations or slots so as to be slidable essentially transversely of the axis of the respective reel.
As a result of the configuration according to the present invention, the cassette acts as a transfer device. For providing the cassette with a new ribbon, the cassette is separated from the device or machine and can be easily provided with a new ribbon reel at a location suitable for this purpose. After actuating a release device, the old reel is moved essentially perpendicularly of the reel axis toward the edge area of the housing and is then removed from the housing. The new reel is then inserted in the opposite direction into the housing. The grooves, integrally formed indentations (e.g., embossments) or slots in the housing walls serve as guide means for the reels or the shafts thereof. Subsequently, the ribbon is guided onto the new empty reel which has also been inserted in the same manner and is attached to the reel in order to be wound up. For this purpose, the ribbon is guided from the full reel over a ribbon guide means and is attached to a ribbon receiving means for winding up the ribbon. The cassette now provided with the fresh ribbon can then be inserted, for example, into the postage meter machine which is equipped to receive the cassette.
The cassette also facilitates a quick exchange of different ribbons which have not yet been completely used up and serves simultaneously as an intermediate storage unit for ribbon reels which have not been completely used up outside of the device intended to receive the ribbon. This also constitutes an effect of the invention which protects the environment.
The cassette utilizes an especially small quantity of material if the housing is composed essentially only of the two spaced-apart wall portions, wherein one of the wall portions may be constructed double-walled for receiving auxiliary means, such as a braking element and/or a mechanism for securing the reels. When the contours of the two walls of this double-walled construction are selected differently, the quantity of material is further reduced.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention.